In U.S. Pat. No. 4,418,123--Bunnelle et al., an extrudable self-adhering elastic is disclosed. It is disclosed therein that the material may be utilized to provide elasticity to disposable garments by stretching the material and applying it to a deformable substrate. This material has been difficult to utilize in high-speed formation of diapers and other disposable garments as when it is stretched it will not adhere well to polymer substrates without pressure being applied to the material as it is applied to the substrate. Further, there has been no practical way of applying the material in contoured patterns such as circular patterns onto the deformable substrates. It is desirable that elastic be contoured for use in disposable garments such as diapers, face masks and disposable hats.
It is known in the formation of disposable diapers that elastic may be applied to the diaper to form elasticized areas at the legs and at the waist. However, as illustrated in U.S. Pat. No. 4,227,952--Sabee, U.S. Pat. No. 4,050,462--Woon et al., and in U.S. Pat. No. 3,860,003--Buell, the placement of elastics is ordinarily in straight lines. There has been proposed in U.S. Pat. No. 3,828,367-- Bourgeois, a method of forming elastics on disposable clothes by placing the elastic into grooves in a roller from which it is applied to the garment.
There remains a need for a method and apparatus for applying curved elastic easily to a continuous web. There also particularly is a need for a method of accurately applying generally circular self-adhering elastic to substrates.